Sen. Marco Rubio continued lobbing grenades at Donald Trump on Friday night, calling the Republican front-runner for a "clown" after being on the receiving end of the billionaire's insults.

During yet another of his rowdy rallies, Trump told supporters in Fort Worth that Rubio is a "little frightened puppy" and a "nervous basket case" before turning the attention to how sweaty the Florida senator is.

In response, Rubio kept up attacks from rallies and TV appearances following the debate, telling Fox News' Bret Baier that Trump is a "con man" and a "dream" for the Democrats in November if he wins the GOP's presidential nomination.

"He's a clown," Rubio said laughing. "Look, I saw him backstage. He was nervous. He was waving his arms around. He was huddling around with someone in the corner. He asked for a full length mirror at one point. If people watched the debate last night, they'll know for a fact that not only was I not nervous, but it's time to take the mask off of this guy."

"He's being unmasked and obviously he doesn't like it, and no one's done that to him before, but we can't let this go on," Rubio told Baier. "He's the front-runner now, and I think it is unacceptable that the front-runner is a guy that's a con-man, and he's trying to take over the party of [Ronald] Reagan. We're not going to let that happen ... He's a dream for the Democrats."

The Florida senator also spoke highly of New Jersey Gov. Chris Christie, who endorsed Trump earlier Friday in a surprise endorsement. Rubio said his New Hampshire nemesis is a "talented communicator," before using that phrase against Trump after Thursday's debate.

"They probably called him in to help Donald after a very rough evening last night and a rough day on the trail today," Rubio told the Fox anchor.